Lung ultrasound for detection of increased extravascular lung water, cardiac and non-cardiac patients who underwent non-cardiac surgical procedures

Abstract

Maja Karaman Ilic

Aim: Prevention of post-operative cardio-respiratory deterioration in cardiac and non-cardiac patients who have undergone non-cardiac surgical procedure due to perioperative fluid overload.

Introduction: Induction in general anaesthesia (GA) drives patients in hypotension. Vasodilation, particularly veno-dilatation, is the primary cause of relative hypovolemia produced by anaesthetic drugs. Relative hypovolemia is a consequence of increased venous compliance, decreased venous return and reduced response to vasoactive substances. Maintenance of adequate cardiac output (CO) and arterial blood pressure are vital for preserving tissue perfusion and oxygen delivery (DO2). To preserve CO and adequate organ perfusion, anaesthesiologists may choose between liberal perioperative fluid approach and a restrictive one with small dose of vasoactive drugs. Each choice carries its own risks. In general, a liberal perioperative volume replacement strategy is more common choice. As a consequence of selected therapy, fluid overload is often seen. The clinically most significant complication of excessive volume is “Lung -Swelling” respectively pulmonary oedema. Standard monitoring that includes clinical exam, chest
X ray, oxygen saturation of peripheral blood (SpO2) and blood lactate level lacks sensitivity and specificity for pulmonary oedema diagnose. Additionally, those are late indicators of tissue and organ hypo- perfusion. Lung ultrasound provides high diagnostic sensitivities and specificities in detecting various lung pathologies: Interstitial syndrome,  neumothorax and alveolar consolidation. Interstitial syndrome represents a variety of clinical situations, including pulmonary oedema, respiratory distress syndrome, pneumonia
and interstitial diseases. Due to the development of pulmonary oedema, transition of A-profile (normal lung ultrasound finding) to B-profile (that is specific for interstitial syndrome) occurs. These findings enable us to act therapeutically even before the late indicators of cardio-respiratory deterioration appear.

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